Nico Rosberg Quickest In Malaysian Grand Prix Practice (PHOTOS)

Formula 1 championship leader Nico Rosberg has set the pace ahead of Sunday's Malaysian Grand Prix after putting down the fastest time in second practice at the Sepang International Circuit.

The Mercedes driver, who comfortably won the season-opening Australian Grand Prix a fortnight ago, posted a lap time of 1min39.909secs, with Ferrari's Kimi Raikkonen and Red Bull's four-time title holder Sebastian Vettel not far behind.

Nico Rosberg hopes to build on his Australian GP success at Sepang this weekend

Raikkonen, appearing strong at this venue where temperatures hit 34 degrees centigrade after a disappointing second debut on his return to Ferrari this season, finished just 0.035secs adrift.

As for Vettel, whose race at Melbourne's Albert Park ended after only a handful of laps due to a cylinder failure in the Renault engine, the 26-year-old finished 0.061secs down on German compatriot Rosberg.

In spite of his speed, Rosberg admitted to problems that needed resolving ahead of qualifying.

"It was crazy conditions out there," he said. "I the very, very warm temperatures, it's a huge challenge to get everything right. The cars are on the edge and the tyre degradation was higher than expected - we are sliding a bit more this year.

"We are still having some issues.. so we still have work to do overnight to improve."